Alone in his study, with fast-locked door, Baron de Grost sat reading word by word with zealous care the dispatch from Paris which had just been delivered into his hands. From the splendid suite of reception-rooms which occupied the whole of the left-hand side of the hall, came the faint sound of music. The street outside was filled with automobiles and carriages setting down their guests. Madame was receiving to-night a gathering of very distinguished men and women, and it was only on very urgent business indeed that her husband had dared to leave her side.

The room in which he sat was in darkness except for the single heavily shaded electric lamp which stood by his elbow. Peter was wearing Court dress, with immaculate black silk stockings, and diamond buckles upon his shoes. A red ribbon was in his button-hole and a French order hung from his neck. His passion for clothes was certainly amply ministered to by the exigencies of his new position. Once more he read those last few words of this unexpectedly received dispatch—read them with a frown upon his forehead and the light of trouble in his eyes. For three months he had done nothing but live the life of an ordinary man of fashion and wealth. His first task—for which, to tell the truth, he had been anxiously waiting—was here before him, and he found it little to his liking. Again he read slowly to himself the last paragraph of Sogrange's letter:—

The music from the reception-rooms grew louder and more insistent. Peter rose to his feet, and, moving to the fireplace, struck a match and carefully destroyed the letter which he had been reading. Then he straightened himself, glanced for a moment at the mirror, and left the room to join his guests.

"Monsieur le Baron jests," the lady murmured. Peter shook his head.

"Indeed, no, madame!" he answered earnestly. "France has offered us nothing more delightful in the whole history of our entente than the loan of yourself and your brilliant husband. Monsieur de Lamborne makes history amongst us politically, whilst madame——"

Peter sighed, and his companion leaned a little towards him. Her dark eyes were full of sentimental regard.

"Yes?" she whispered. "Continue. It is my wish."

"I am the good friend of Monsieur de Lamborne," Peter said, and in his tone there seemed to lurk some far-away touch of regret, "yet madame knows that her conquests here have been many."

The ambassador's wife fanned herself and remained silent for a moment, a faint smile playing at the corners of her full, curving lips. She was indeed a very beautiful woman—elegant, a Parisian to the finger-tips, with pale cheeks but eyes dark and soft; eyes trained to her service, whose flash was an inspiration, whose very droop had set beating the hearts of men less susceptible than the Baron de Grost. Her gown was magnificent, of amber satin—a colour daring but splendid; the outline of her figure as she leaned slightly back in her seat might indeed have been traced by the inspired finger of some great sculptor. Peter, whose reputation as a man of gallantry was well established, felt the whole charm of her presence—felt, too, the subtle indications of preference which she seemed inclined to accord to him. There was nothing which eyes could say which hers were not saying during those few minutes. Peter, indeed, glanced around a little nervously. His wife had still her moments of unreasonableness; it was just as well that she was engaged with a party of her guests at the farther end of the apartments!

"You are trying to turn my head," his beautiful companion whispered. "You flatter me."

"It is not possible," he answered.

Again the fan fluttered.

"Ah, monsieur," she continued, dropping her voice until it scarcely rose above a whisper, "there are not many men like you. You speak of my husband and his political gifts. Yet, what, after all, do they amount to? What is his position, indeed, if one glanced behind the scenes, compared with yours?"

The face of the Baron de Grost became like a mask. It was as though suddenly he had felt the thrill of danger close at hand—danger even in that scented atmosphere wherein he sat.

"Alas, madame!" he answered, "it is you now who are pleased to jest. Your husband is a great and powerful ambassador. I, unfortunately, have no career, no place in life, save the place which the possession of a few millions gives to a successful financier."

She laughed very softly, and again her eyes spoke to him.

"Monsieur," she murmured, "you and I together could make a great alliance; is it not so?"

"Madame," he faltered doubtfully, "if one dared hope——"

Once more the fire of her eyes, this time not only voluptuous. Was the man stupid or only cautious?

"If that alliance were once concluded," she said softly, "one might hope for everything."

"If it rests only with me," he began seriously, "oh, madame!"

He seemed overcome. Madame was gracious; but was he really stupid or only very much in earnest?

"To be one of the world's money kings," she whispered, "it is wonderful, that. It is power—supreme, absolute power! There is nothing beyond—there is nothing greater."

Then Peter, who was watching her closely, caught another gleam in her eyes, and he began to understand. He had seen it before amongst a certain type of her countrywomen—the greed of money. He looked at her jewels, and he remembered that, for an ambassador, her husband was reputed to be a poor man. The cloud of misgiving passed away from him; he settled down to the game.

"If money could only buy the desire of one's heart!" he murmured. "Alas!"

His eyes seemed to seek out Monsieur de Lamborne amongst the moving throngs. She laughed softly, and her hand brushed his.

"Money and one other thing, Monsieur le Baron," she whispered in his ear, "can buy the jewels from a crown—can buy even the heart of a woman."

A movement of approaching guests caught them up and parted them for a time. The Baroness de Grost was at home from ten till one, and her rooms were crowded. Peter found himself drawn on one side a few minutes later by Monsieur de Lamborne himself.

"I have been looking for you, de Grost," the latter declared. "Where can we talk for a moment?"

His host took the ambassador by the arm and led him into a retired corner. Monsieur de Lamborne was a tall, slight man, somewhat cadaverous-looking, with large features, hollow eyes, thin but carefully arranged grey hair, and a pointed grey beard. He wore a frilled shirt, and an eyeglass suspended by a broad, black ribbon hung down upon his chest. His face, as a rule, was imperturbable enough, but he had the air just now of a man greatly disturbed.

"We cannot be overheard here," Peter remarked. "It must be an affair of a few words only, though."

Monsieur de Lamborne wasted no time in preliminaries.

"This afternoon," he said, "I received from my Government papers of immense importance, which I am to hand over to your Foreign Minister at eleven o'clock to-morrow morning."

Peter nodded.

"Well?"

De Lamborne's thin fingers trembled as they played nervously with the ribbon of his eyeglass.

"Listen," he continued, dropping his voice a little. "Bernadine has undertaken to send a copy of their contents to Berlin by to-morrow night's mail."

"How do you know that?"

The ambassador hesitated.

"We, too, have spies at work," he remarked grimly. "Bernadine wrote and sent a messenger with the letter to Berlin. The man's body is drifting down the Channel, but the letter is in my pocket."

"The letter from Bernadine?"

"Yes."

"What does he say?"

"Simply that a verbatim copy of the document in question will be dispatched to Berlin to-morrow evening without fail," replied the ambassador.

"There are no secrets between us," Peter declared, smoothly. "What is the special importance of this document?"

De Lamborne shrugged his shoulders.

"Since you ask," he said, "I tell you. You know of the slight coolness which there has been between our respective Governments? Our people have felt that the policy of your Ministers in expending all their energies and resources in the building of a great fleet, to the utter neglect of your army, is a wholly one-sided arrangement, so far as we are concerned. In the event of a simultaneous attack by Germany upon France and England, you would be utterly powerless to render us any measure of assistance. If Germany should attack England alone, it is the wish of your Government that we should be pledged to occupy Alsace-Lorraine. You, on the other hand, could do nothing for us if Germany's first move were made against France."

Peter was deeply interested, although the matter was no new one to him.

"Go on," he directed. "I am waiting for you to tell me the specific contents of this document."

"The English Government has asked us two questions; first, how many complete army corps we consider she ought to place at our disposal in this eventuality; and, secondly, at what point should we expect them to be concentrated? The dispatch which I received to-night contains the reply to these questions."

"Which Bernadine has promised to forward to Berlin to-morrow night," Peter remarked softly.

De Lamborne nodded.

"You perceive," he said, "the immense importance of the affair. The very existence of that document is almost a casus belli."

"At what time did the dispatch arrive," Peter asked, "and what has been its history since?"

"It arrived at six o'clock," the ambassador declared. "It went straight into the inner pocket of my coat; it has not been out of my possession for a single second. Even whilst I talk to you I can feel it."

"And your plans? How are you intending to dispose of it to-night?"

"On my return to the Embassy I shall place it in the safe, lock it up, and remain watching it until morning."

"There doesn't seem to be much chance for Bernadine," Peter remarked.

"But there must be no chance—no chance at all," Monsieur de Lamborne asserted, with a note of passion in his thin voice. "It is incredible, preposterous, that he should even make the attempt. I want you to come home with me and share my vigil. You shall be my witness in case anything happens. We will watch together."

Peter reflected for a moment.

"Bernadine makes few mistakes," he said thoughtfully.

Monsieur de Lamborne passed his hand across his forehead.

"Do I not know it?" he muttered. "In this instance, though, it seems impossible for him to succeed. The time is so short and the conditions so difficult. I may count upon your assistance, Baron?"

Peter drew from his pocket a crumpled piece of paper.

"I received a telegram from headquarters this evening," he said, "with instructions to place myself entirely at your disposal."

"You will return with me, then, to the Embassy?" Monsieur de Lamborne asked eagerly.

Peter did not at once reply. He was standing in one of his characteristic attitudes, his hands clasped behind him, his head a little thrust forward, watching with every appearance of courteous interest the roomful of guests, stationary just now, listening to the performance of a famous violinist. It was, perhaps, by accident that his eyes met those of Madame de Lamborne, but she smiled at him subtly—more, perhaps, with her wonderful eyes than with her lips themselves. She was the centre of a very brilliant group, a most beautiful woman holding court, as was only right and proper, amongst her admirers. Peter sighed.

"No," he said, "I shall not return with you, de Lamborne. I want you to follow my suggestions, if you will."

"But, assuredly——"

"Leave here early and go to your club. Remain there until one, then come to the Embassy. I shall be there awaiting your arrival."

"You mean that you will go there alone? I do not understand," the ambassador protested. "Why should I go to my club? I do not at all understand!"

"Nevertheless, do as I say," Peter insisted. "For the present, excuse me. I must look after my guests."

The music had ceased, there was a movement towards the supper room. Peter offered his arm to Madame de Lamborne, who welcomed him with a brilliant smile. Her husband, although, for a Frenchman, he was by no means of a jealous disposition, was conscious of a vague feeling of uneasiness as he watched them pass out of the room together. A few minutes later he made his excuses to his wife, and, with a reluctance for which he could scarcely account, left the house. There was something in the air, he felt, which he did not understand. He would not have admitted it to himself, but he more than half divined the truth. The vacant seat in his wife's carriage was filled that night by the Baron de Grost.

At one o'clock precisely Monsieur de Lamborne returned to his house, and found de Grost gazing with obvious respect at the ponderous safe let into the wall.

"A very fine affair—this," he remarked, motioning with his head towards it.

"The best of its kind," Monsieur de Lamborne admitted. "No burglar yet has ever succeeded in opening one of its type. Here is the packet," he added, drawing the document from his pocket. "You shall see me place it in safety."

Peter stretched out his hand and examined the sealed envelope for a moment closely. Then he moved to the writing-table, and, placing it upon the letter scales, made a note of its exact weight. Finally he watched it deposited in the ponderous safe, suggested the word to which the lock was set, and closed the door. Monsieur de Lamborne heaved a sigh of relief.

"I fancy this time," he said, "that our friends at Berlin will be disappointed. Couch or easy-chair, Baron?"

"The couch, if you please," Peter replied, "a strong cigar, and a long whisky and soda. So! Now for our vigil."

The hours crawled away. Once Peter sat up and listened.

"Any rats about?" he inquired.

The ambassador was indignant.

"I have never heard one in my life," he answered. "This is quite a modern house."

Peter dropped his match-box and stooped to pick it up.

"Any lights on anywhere except in this room?" he asked.

"Certainly not," Monsieur de Lamborne answered. "It is past three o'clock, and every one has gone to bed."

Peter rose and softly unbolted the door. The passage outside was in darkness. He listened intently for a moment, and returned yawning.

"One fancies things," he murmured apologetically.

"For example?" de Lamborne demanded.

Peter shook his head.

"One mistakes," he said. "The nerves become over-sensitive."

The dawn broke, and the awakening hum of the city grew louder and louder. Peter rose and stretched himself.

"Your servants are moving about in the house," he remarked. "I think that we might consider our vigil at an end."

Monsieur de Lamborne rose with alacrity.

"My friend," he said, "I feel that I have made false pretences to you. With the day I have no fear. A thousand pardons for your sleepless night."

"My sleepless night counts for nothing," Peter assured him; "but before I go, would it not be as well that we glance together inside the safe?"

De Lamborne shook out his keys.

"I was about to suggest it," he replied.

The ambassador arranged the combination and pressed the lever. Slowly the great door swung back. The two men peered in.

"Untouched!" de Lamborne exclaimed, a little note of triumph in his tone.

Peter said nothing, but held out his hand.

"Permit me," he interposed.

De Lamborne was conscious of a faint sense of uneasiness. His companion walked across the room and carefully weighed the packet.

"Well?" de Lamborne cried. "Why do you do that? What is wrong?"

Peter turned and faced him.

"My friend," he said, "this is not the same packet."

The ambassador stared at him incredulously.

"This packet can scarcely have gained two ounces in the night," Peter went on. "Besides, the seal is fuller. I have an eye for these details."

De Lamborne leaned against the back of the table. His eyes were a little wild, but he laughed hoarsely.

"We fight, then, against the creatures of another world," he declared. "No human being could have opened that safe last night."

Peter hesitated.

"Monsieur de Lamborne," he said, "the room adjoining is your wife's?"

"It is the salon of madame," the Ambassador admitted.

"What are the electrical appliances doing there?" Peter demanded. "Don't look at me like that, de Lamborne. Remember that I was here before you arrived."

"My wife takes an electric massage every day," Monsieur de Lamborne answered in a hard, unnatural voice. "In what way is Monsieur le Baron concerned in my wife's doings?"

"I think that there need be no answer to that question," Peter said quietly. "It is a greater tragedy which we have to face. I maintain that your safe was entered from that room. A search will prove it."

"There will be no search there," de Lamborne declared fiercely. "I am the ambassador of France, and my power under this roof is absolute. I say that you shall not cross that threshold."

Peter's expression did not change. Only his hands were suddenly outstretched with a curious gesture—the four fingers were raised, the thumbs depressed. Monsieur de Lamborne collapsed.

"I submit," he muttered. "It is you who are the master. Search where you will."

"Monsieur has arrived?" the woman demanded breathlessly.

The proprietor of the restaurant himself bowed a reply. His client was evidently well known to him.

"Monsieur has ascended some few minutes ago."

The woman drew a little sigh of relief. A vague misgiving had troubled her during the last few hours. She raised her veil as she mounted the narrow staircase which led to the one private room at the HÔtel de Lorraine. Here she was safe; one more exploit accomplished, one more roll of notes for the hungry fingers of her dress-maker.

She entered, without tapping, the room at the head of the stairs, pushing open the ill-varnished door with its white-curtained top. At first she thought that the little apartment was empty.

"Are you there?" she exclaimed, advancing a few steps.

The figure of a man glided from behind the worn screen close by her side and stood between her and the door.

"Madame!" Peter said, bowing low.

Even then she scarcely realised that she was trapped.

"You!" she cried. "You, Baron! But I do not understand. You have followed me here?"

"On the contrary, madame," he answered; "I have preceded you."

Her colossal vanity triumphed over her natural astuteness. The man had employed spies to watch her! He had lost his head. It was an awkward matter, this, but it was to be arranged. She held out her hands.

"Monsieur," she said, "let me beg you now to go away. If you care to, come and see me this evening. I will explain everything. It is a little family affair which brings me here."

"A family affair, madame, with Bernadine, the enemy of France," Peter declared gravely.

She collapsed miserably, her fingers grasping at the air; the cry which broke from her lips harsh and unnatural. Before he could tell what was happening, she was on her knees before him.

"Spare me!" she begged, trying to seize his hands.

"Madame," Peter answered, "I am not your judge. You will kindly hand over to me the document which you are carrying."

She took it from the bosom of her dress. Peter glanced at it and placed it in his breast-pocket.

"And now?" she faltered.

Peter sighed—she was a very beautiful woman.

"Madame," he said, "the career of a spy is, as you have doubtless sometimes realised, a dangerous one."

"It is finished!" she assured him breathlessly. "Monsieur le Baron, you will keep my secret? Never again, I swear it, will I sin like this. You will not tell my husband?"

"Your husband already knows, madame," was the quiet reply. "Only a few hours ago I proved to him whence had come the leakage of so many of our secrets lately."

She swayed upon her feet.

"He will never forgive me!" she cried.

"There are others," Peter declared, "who forgive more rarely even than husbands."

A sudden illuminating flash of horror told her the truth. She closed her eyes and tried to run from the room.

"I will not be told!" she screamed. "I will not hear. I do not know who you are. I will live a little longer!"

"Madame," Peter said, "the Double Four wages no war with women, save with spies only. The spy has no sex. For the sake of your family, permit me to send you back to your husband's house."

That night two receptions and a dinner party were postponed. All London was sympathising with Monsieur de Lamborne, and a great many women swore never again to take a sleeping draught. Madame de Lamborne lay dead behind the shelter of those drawn blinds, and by her side an empty phial.